The television has been developed from the beginning of 20th century, wherein the black and white one, the color one, and even the digital television were disclosed for continuously progresses. Human beings keep challenging to improve the science and technology for developing the better vision. In 21st century, people still strive for developing new displaying technique, wherein the new generation displayer could provide more colorful and finer vision.
According to the prior art, the display, such as CRT TV, PC monitor, LCD TV, and PDP TV, is based on 2-D displaying technique. However, the human vision is based on stereoscopy. For achieving the purpose of stereoscopy, it is important to estimate the depth of objects while the stereo image is taken by a camera. For solving the above problem, U.S. Pat. No. 6,959,253 described a method for calibrating machine vision measuring systems that have more than one camera. Furthermore, U.S. Pat. No. 6,781,618 discloses a method consisting of the construction of a 3D scene model by acquiring first images of a scene having unknown characteristics with a first camera. Corresponding second images of another scene having known characteristics are acquired by a second camera. The first and second cameras have a fixed physical relationship to each other. The 3D model should be analyzed by means of using the corresponding positions and the fixed physical relationship of two cameras.
Please refer to FIG. 1. It illustrates a block diagram showing the electrical construction of the stereo-image capturing device of U.S. Pat. No. 6,977,674. As shown in FIG. 1, a CCD with the RGB on-chip color filter 14 attached is utilized for the imaging device 11. Namely, the color filters which are applied to the apertures 22R, 22G, and 22B correspond to the color filters which are utilized for the imaging device 11. Image signals which are detected in the imaging device (CCD) 11 are fed to the image processing unit 30, so that the signals are converted from analog signals to digital signals and then subjected to predetermined signal processing. An image capturing operation of the stereo-image capturing device and an image data recording operation for the recording medium M are controlled in accordance with the operations at the operation switch group 34. Although there is merely one camera lens introduced for capturing stereo image, the camera lens should be designed in a specific and complex shape and further performed with a lot of limited devices.
The above-mentioned apparatus are performed for capturing stereo image by means of using several calibrated lens, wherein the apparatus are larger and more complicated. Therefore, image-calibrating is considered to achieve the purpose of 3D image reconstruction. The 3D image reconstruction method includes the steps of registering an orthographic image of a scene, combining a photogrammetric image and a technical drawing of the scene to form a co-registered orthographic and perspective (COP) image, and reconstructing a 3D image from the COP image. However, the photogrammetric image should be taken by several cameras at first.
In U.S. Pat. No. 6,724,930, it discloses a three-dimensional position and orientation sensing apparatus. Please refer to FIG. 2. It illustrates a block diagram for showing a structure of a three-dimensional position and orientation sensing apparatus according to U.S. Pat. No. 6,724,930. As illustrated in FIG. 2, a plurality of markers 2 (hereinafter to be abbreviated as code markers) having unique geometric characteristics are disposed on or near an object of which three-dimensional position and orientation is to be estimated. These code markers 2 are photographed by an image acquisition apparatus 3, and a photographed image 5 is transferred to within a computer 4. In principle, the object 1 and the image acquisition apparatus 3 have their own coordinate systems, and the image 5 acquired by the image acquisition apparatus 3 is defined as a camera image plane. However, the image 5 should be further dealt by the computer. After the computer 4 has received the image 5, the computer 4 extracts a candidate region that is estimated to be a region corresponding to the code marker 2, from within the image 5. The computer 4 analyzes in detail the candidate region extracted, and then computes geometric characteristics corresponding to the code of the code marker 2 from the candidate region. When the code has been recognized, the computer registers the position within the image and the code by recognizing this region as the marker region. Finally, the computer 4 calculates a three-dimensional position and orientation of the object 1 with respect to the image acquisition apparatus 3, by utilizing the two-dimensional image position of the code marker 2 extracted from the image registered at the step 2 and the three-dimensional position of this code marker 2 with respect to the object 1. Meanwhile there is a lot of operation introduced in computer analyzing.
However, in practice, the prior art should perform 3D depth-capturing by means of introducing more than one camera, a lot of complex calibrated lens or a lot of program operation of computer. It is difficult to implement. Hence, it needs to provide a system and method for obtaining object depth through digital signal processing, which provides disparity vectors and camera extrinsic parameters for obtaining the depth is obtained from a disparity to depth conversion module, simplifies the entire structure and process, is capable of achieving the purpose of automatically obtaining object depth without change of the camera itself, thereby facilitating user to take stereo image, and can rectify those drawbacks of the prior art and solve the above problems.